1. Field of the Invention
This invention relates to improvements for a power spade and particularly to a portable power spade which is adapted to be operated by a single operator.
2. Prior Art
Many mechanical and power tools have been developed for the construction industry. However, most power tools are designed for large scale uses and are not adapted to be utilized on hand power tool job which require only one man. Because todays labor costs are high, methods need to be devised to enable laborers to perform more work in the same amount of time. Regardless of the amount of developed power equipment available on the market today, many jobs still require individual one-man care. This is especially true in many jobs requiring the use of pick and shovels.
Very few tools have been developed which mechanically perform the task that are required by a single man utilizing a pick and a shovel. One example of such a device is my invention which was issued U.S. Pat. No. 2,890,532. This invention discloses a portable one-man operated shovel having an upright frame and supporting an endless conveyor which has a number of buckets disposed thereon. A small engine is attached to the frame and drives the conveyor.
Although the basic concept of my previous invention performed adequately as a manual power digger, several problems resulted from its construction. The buckets disclosed therein are solid trapezoidal shaped buckets which are pivoted on a cam and dump the dirt therefrom by tilting to one side. These buckets are mounted to a wire formed chain which rotates about specially made sprockets. When either the buckets or the chain need to be replaced or repaired special parts are required. In addition, the solid shaped buckets which tilt to empty the soil also serve as cutting instruments, and sometimes become damaged in digging such that they will not properly rotate about their axis and empty of the dirt contained therein. Another problem arose in the stirrup and lever assembly because of the difficulty of moving the power spade when digging a ditch or trench.
The present invention solves these problems involved in the prior art and provides improvements which enable a manual power spade to be properly used for digging in restricted areas, for digging trenches, post holes and other types of excavations. Besides solving the problems of the prior art, the present invention provides several new features which make the power digger more desirable.